The ISO week date system is part of the ISO 8601 standard for date and time representation. It's widely used in business, especially in Europe, for scheduling, payroll, and planning purposes. Unlike the traditional Gregorian calendar where the first week of the year can be partial, ISO weeks are always complete 7-day periods starting on Monday.

ISO week dates are particularly useful for business applications where week-based planning is essential. They're commonly used in manufacturing for production schedules, in logistics for delivery planning, and in many European countries for official documentation and reporting.